1. Field of Invention
Embodiments described herein relate generally to synchronized audio/video decoding for network devices.
2. Discussion of the Related Art
Various schemes have been proposed for distributing media information (e.g., video data, audio data, etc.) along communication links within a media network. One type media network is a powerline network that essentially uses the AC electrical wiring of a house (i.e., the powerline) as a transmission medium. Accordingly, within a powerline network, a network server can transmit media information (i.e., one or more encoded data streams) to one or more network clients that are “plugged in” to AC electrical outlets within a house. The network clients receive and decode the encoded data stream and output the decoded data stream in an audio and/or video format.
One drawback to conventional powerline networks is that network clients have no synchronization mechanism. Thus, even when two network clients begin decoding an encoded data stream at the same time, a delay between them gets gradually larger over time because oscillators of the locks within the decoders operate independently. If the audio delay becomes larger than 30 msec, an undesirable echo effect (i.e., the Haas Effect) occurs, resulting in the user hearing two audio tones. Such an echo effect undesirably detracts from the user's enjoyment of music being played in surround-sound audio decoding systems. The accuracy of a typical oscillator within a decoder clock is more than 10 parts per million (ppm). One hour is 3600 seconds. Therefore, 10 ppm is equivalent to 36 msec. Accordingly, conventional powerline networks will exhibit the undesirable Hass Effect within one hour of decoding audio data.
Accordingly, it would be beneficial to provide a method and system adapted to synchronize operations of decoders within a network.